Cellulose-ether solvent and composition



WILLIAM R. WEBB, OF ROCHESTER, NEW YORK, ASSIGNOR TO EASTMAN KODAK COMPANY, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

CELLULOSE-ETHER SOLVENT AND COMPOSITION.

No Drawing.

To all whom it may concern:

Be it known that I, \VILLIAM R. WEBB, a citizen of the United States of America, residin at Rochester, in the county of Monroe and tate of New York, have invented certain new and useful Improvements in Cellulose-Ether Solvents and Compositions, of which the following is a full, clear, and exact specification.

This invention relates to solvents for making strong solutions of cellulose ether and also relates to the cellulose ether compositions produced by the aid of such solvents. One object of my invention is to provide a solvent which will dissolve such large proportions of cellulose ethers that thick or viscous flowable solutions may be obtained for use in plastic and film making arts. Another object of my invention is to provide a cellulose ether solution which may be manufactured into strong, flexible, transparent film on the machines and by the methods now in use.

In U. S. Patent No. 1,188,376, Lilienfeld, June 20, 1916, there are disclosed a series of alkyl ethers of cellulose. Certain of these are practically insoluble in water, and my invention relates to the ethers having that property. \Vhile such ethers form thin solutions in ethyl alcohol or carbon tetrachlorid, it has been found that such single solvents by themselves will not dissolve a sufficient proportion of the ethers tomake a desirably thick, flowable composition or dope. such as may be used in the manufacture of photographic film base by the customary methods. I have discovered that an adequately strong and useful solvent may be prepared by mixing these substances. The mixtures may vary from one containing 95% of ethyl alcohol and 5% of carbon tetrachlorid to one that consists of 95% carbon tetrachlorid and 5%"ethyl alcohol. the

proportions being by weight. Outside of this range of proportions the combinations of these substances give weaker solutions from which undesirable film is formed.

I will now describe the preferred embodi- Specification of Letters Patent.

Application filed January 10, 1921.

Patented Junie 6,1922.

Serial No. 436,309.

ment of my invention by way of illustration. I mix carbon tetrachlorid and ethyl alcohol in the proportion of 60 parts of the former to 40 partsof the latter by weight and dissolve ethyl cellulose therein until a thick, viscous, fiowable solution thereof is obtained. Other substances which impart suppleness, or incombustibility, or other qualities to the film may be then added to the dope, such modifying a ents being, for example, triphenyl- *phospliate, camphor, monochlornaphthalene or tricresyl phos phate.

The ingredients are of the ordinary com mercial type and sufiiciently purified for the process of film manufacture, so asto give adope yielding films having the proper relative freedom from color. The viscous-flowable dope above described can be used in connection with the usual film-forming apparatus without the necessity of expensive alterations in the latter.

Having thus described my inventionpvhat I claim as new and desire to secure by Letters Patent is:

1. A flowable film-forming composition, comprising cellulose ether dissolved in a mixture of carbon tetrachlorid and a monohydroxy aliphatic alcohol of less than 3 carbon atoms.

2. A viscous fiowable film-forming composition, comprising an alkyl ether of cellulose dissolved in a mixture of carbon tetrachlorid and ethyl alcohol.

3. A viscous flowable' film-forming composition, comprising an alkyl ether of cellulose dissolved in a compound solvent comprising from 5 to 95 parts'of carbon tetrachlorid and 95 to 5 parts by weight of ethyl alcohol.

4. A viscous flowable film-forming composition. comprising ethyl cellulose dissolved in a compound solvent comprising approximately 60 parts by weight of carbon tetrachlorid to 40 parts of ethyl alcohol.

Signed at Rochester, New York, this 5th day of- January, 1921.

WILLIAM R. WEBB. 

